1. Field of the Invention
The present invention relates to a network processor and a host system which operate together to capture all Internet Protocol (IP) communications on a link of a high-speed packet network and provide, for example, a quality of service analysis or flow analysis of the captured communications. The communications might be, for example, voice over Internet Protocol (VOIP) telephone calls.
2. Description of the Related Art
Communications are often transmitted over a high-speed, packet network. For example, a communication might be a voice over Internet Protocol (VOIP) telephone call comprised of signaling packets and corresponding Internet Protocol (IP) packet media streams. The signaling packets include information indicating, for example, when the VOIP telephone call is initiated, when the VOIP telephone call ends, what parties are participating in the VOIP telephone call, etc. The signaling packets would typically be based on a signaling protocol such as, for example, SIP. SIP is a well-known protocol used for signaling packets of a VOIP telephone call. However, many other signaling protocols are available.
The packet media streams (often referred to as “flows”) are formed of media packets which carry data. If the communication is a VOIP telephone call, the media packets would typically be real-time protocol (RTP) packets. RTP is a well-known protocol used for media packets of a VOIP telephone call.
FIG. 1 is a diagram illustrating the use of a call signaling analyzer to monitor a VOIP telephone call. Referring now to FIG. 1, a call signaling analyzer 4 is directly connected to a network link 6 of a network under test. Call signal analyzer 4 can detect the signaling packets (i.e., the SIP packets) for a respective VOIP telephone call transmitted over network link 6.
However, call signaling analyzer 4 cannot detect the packet media streams (i.e., the RTP packets). Therefore, with call signaling analyzer 4 in FIG. 1, only information conveyed by the signaling packets can be monitored. For example, from the signaling packets, it can be determined when the VOIP telephone call is initiated, when the VOIP telephone call ends, what parties are participating in the VOIP telephone call, etc.
Unfortunately, since call signaling analyzer 4 cannot detect the packet media streams, call signaling analyzer 4 cannot analyze or monitor information conveyed by the packet media streams.
Further, since the processing power of call signaling analyzer 4 is relatively limited, call signaling analyzer 4 can be overwhelmed by all the packets traveling on network link 6. For this reason, call signaling analyzer is typically used to detect and monitor the signaling packets for only a single, respective VOIP telephone call at one time, and cannot simultaneously detect and monitor the signaling packets for all the VOIP telephone calls being transmitted through network link 6.